Final answer:
Bacteria causing disease is not an example of microbial antagonism, which includes mechanisms like acid production, bacteriocin production, and occupying host receptors.
Step-by-step explanation:
Microbial antagonism refers to the competition between microbes where one microbe inhibits or interferes with the growth of another through various mechanisms. These mechanisms may include acid production, bacteriocin production, and occupying host receptors to outcompete pathogens. Among the options provided, 'Bacteria causing disease' is not an example of microbial antagonism; it refers to pathogenesis rather than a defensive interaction between microbes.